This invention relates to apparatus for providing data communication services, and in particular, to providing fractional bandwidth data communication services.
Data communication vendors typically sell data communication link bandwidth to end users in “full lot” quantities, i.e., an end user is required to purchase an entire unit of bandwidth. For example, an end user that desires to use any portion of a Gigabit Ethernet (GBE) link is required to purchase the entire 1.25 Gigabit per second (GBPS) bandwidth thereof. In some instances however, an entire unit of bandwidth of a data communications link may exceed the required bandwidth of the data to be transmitted by the end user. In this case, the end user is unable to make use of the entire purchased bandwidth resulting in a waste of economic resources of the end user and a waste of bandwidth for the service provider. Having to purchase an entire GBE link may discourage some end users from purchasing bandwidth from a high capacity data link provider. As an alternative, a end user may purchase a full unit of bandwidth from a data communications provider that utilizes smaller bandwidths, i.e., lower capacity data links, thus foregoing the advantages of a higher bandwidth data connection that may provide the end user with a competitive advantage.
In another situation where the difference between the aggregate bandwidth and the full rate data bandwidth of the client I/O module ports can result in a number of ports that can be aggregated into a single higher capacity link. For example, in a ESCON/SONET example, a single 12-port ESCON device could aggregate all 12 ports into a single 2.5 Gb/s OC-48 device, but it may be more attractive to use 4 ESCON devices to aggregate 48 ports into a single 10 Gb/s device.
Currently, the public switched telephone network (PSTN) uses synchronous optical networking (SONET) links that operate at a data rate of approximately 10 GBPS using a single OC-192 link or four OC-48 links. Typically, a telecommunications service provider will aggregate the data of two or more end users together in order to maximize the use of the available bandwidth on the PSTN. In the case of end users operating GBE links at approximately 1 GBPS, a maximum of 10 end users may be aggregated together to form a 10 GBPS signal for transmission across the PSTN. If one or more end users are unable to fully utilize their portion of the 10 GBPS bandwidth, neither the telecommunications provider nor the end user is maximizing the use of the available bandwidth.
The ability to provide fractional portions of high bandwidth capacity links, such as GBE links, to end users would allow them to utilize the advantages of high bandwidth data communications systems without requiring the end users to purchase bandwidth in full unit quantities. The data communications vendors would achieve a more efficient use of the available bandwidth as well, in addition to increasing the number of clients making use of their service. Thus, offering fractional bandwidths of high capacity links would offer advantages to both the suppliers of data communications services and the consumers those services.
However as discussed above, the currently existing equipment is not designed to accommodate fractional bandwidth usage. The development of new equipment to accommodate fractional bandwidth use by end users is both expensive and time consuming. Merely scaling the existing equipment to allow addition of many more users through adding additional input-output ports is not a viable alternative. Adding additional input-output ports to the existing equipment designs will require a much higher pin count than current equipment allows to accommodate the new users. In addition, each of the added input-output ports will require an additional interface circuit associated with each port, larger internal multiplexers and more memory. This additional circuitry will result in a larger chip area, more power and heat to dissipate, and an increase in the cost of the chips.
Therefore, it would be advantageous to provide for the aggregation of users to make use of a fractional high capacity data communication environment using existing equipment that does not require an increase in pin count, power dissipation, and additional circuitry.